Tools

Channel Area

Service Product Area

Forum Affairs

Can the hosts and devices on the same user network segment run different versions of IGMP

11

IGMP has three versions, namely IGMPv1, IGMPv2, and IGMPv3. Different IGMP versions run on devices and hosts are compatible, but all the devices on the same network segment must run IGMP of the same version. If the versions of IGMP run on the devices on the same network segment are different, IGMP member relationships are chaotic.

Run the display igmp interface interface-type interface-number command on all the devices on the same network segment to check the versions of IGMP run on the devices. If the versions are not the same, modify the configuration.

Other related questions:

Addresses on the same network segment cannot be allocated to interfaces on an AR.
Interfaces on an AR can be configured with IP addresses on network segments that overlap. For example, an interface is assigned IP address 20.1.1.1/16. When you configure IP address 20.1.1.2/24 for the other interface, the system displays a message. However, the configuration is successful. When you configure IP address 20.1.1.2/16 for the other interface, the system displays a message indicating that the address conflicts. The configuration fails.
The primary and secondary addresses of an interface can be on network segments that overlap, but must be different. For example, an interface is configured with the primary IP address 20.1.1.1/24. When you configure the secondary IP address 20.1.1.2/16, the system displays a message. However, the configuration is successful.
The primary and secondary addresses of interfaces can be on network segments that overlap, but must be different. For example, an interface is configured with IP address 20.1.1.1/16. When you configure IP address 20.1.1.2/24, the system displays a message. However, the configuration is successful.

IGMP runs on the last-hop router to collect users' requests for programs. The requested multicast data is then sent from the multicast source to users through PIM.
IGMP has three versions.
1. IGMPv1
IGMPv1 defines the General Query message and Report message. A user sends Report message to request a program. After the last-hop router receives the Report message, it adds the user to the specified multicast group and sends General Query messages at intervals to maintain the membership of the user. If the router does not receive any Report message from the user within two intervals, it considers that the user does not require the multicast data and deletes the user from the multicast group.
2. IGMPv2
In IGMPv1, if a user does not require data of a multicast group, it leaves the multicast group after two intervals for sending General Query messages. Multicast data is still sent to the user in this period, wasting bandwidth. IGMPv2 improves IGMPv1 by adding two types of messages: Leave message and Special Query message.
When a user does not require data of a multicast group, the user sends a Leave message to the last-hop router. When a port of the router receives the Leave message, the router sends some Group-Specific Query messages (the quantity is specified by the robustness variable) to the interface to check whether other users in the broadcast domain on the interface require data of the multicast group. If another user requires data of the multicast group, the user replies with a Report message. When receiving the Report message, the router retains the interface. If no Report message is received, the router deletes the interface from the multicast forwarding entry.
IGMPv2 is the most widely used one on networks.
3. IGMPv3
IGMPv1 and IGMPv2 messages contain only the multicast group addresses of the requested programs. If multiple multicast sources provide data with the same multicast group address, data of all the groups is transmitted to users. Users may not see the programs they request. IGMPv3 solves this problem.
IGMPv3 adds a source list in the Report message and supports the following six types of source lists:
-Include: accepts data provided by the multicast sources in the list.
-Exclude: rejects the multicast group data provided by all sources in the list.
-ChangeToInclude: starts to accept multicast group data provided by the multicast sources in the list (previously rejects the data).
-ChangeToExclude: starts to reject multicast group data provided by the multicast sources in the list (previously accepts the data).
-AllowNew: adds a source of which the data is accepted or rejected.
-BlockOld: deletes previous sources of which the data is accepted or rejected.
IGMPv3 replaces the Leave message with the Rep
ort message and adds the Group-and-Source-Specific Query message.

The peer devices on the PPP network can ping each other even if their IP addresses are not in the same network segment. According to the NCP protocol under the PPP protocol, a device can obtain the IP address of its peer device. Therefore, peer devices can ping each other even if their IP addresses are not in the same network segment.